/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2016 pjoc.pub, blademainer.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */

package pub.pjoc.pay.threadpool.impl;

import pub.pjoc.pay.threadpool.ThreadPoolContainer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.List;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

/**
 * Default implementer.
 * @author blademainer
 * @version 2016-08-31 23:16
 */
public class ThreadPoolContainerImpl implements ThreadPoolContainer {
  private static final Logger logger = LoggerFactory
      .getLogger(ThreadPoolContainer.class);

  private ThreadPoolExecutor executorService = new ThreadPoolExecutor(10, 10, 0L,
      TimeUnit.MILLISECONDS,
      new LinkedBlockingQueue<Runnable>());

  public volatile boolean shutdown = false;

  private void shutdown() {
    if (shutdown) {
      logger.error("Thread pool is shutting down!");
      return;
    }
    shutdown = true;
    List<Runnable> runnables = executorService.shutdownNow();
    logger.warn(
        "Shutting down thread pool! least thread size: {} and should be invoke continue!",
        runnables.size());
    for (Runnable runnable : runnables) {
      Thread thread = new Thread(runnable);
      thread.start();
    }
  }

  public void setThreadPool(ThreadPoolExecutor executorService) {
    if (executorService == null) {
      logger.error("ThreadPoolExecutor is null when setting a new one! so dismiss!");
      return;
    }
    this.executorService = executorService;
  }

  @Override
  public void resetPoolSize(int newPoolSize) {
    synchronized (this) {
      if (shutdown) {
        return;
      }
      shutdown();
      executorService = new ThreadPoolExecutor(newPoolSize, newPoolSize, 0L,
          TimeUnit.MILLISECONDS,
          new LinkedBlockingQueue<Runnable>());
      shutdown = false;
    }
  }

  @Override
  public ThreadPoolExecutor getThreadPool() {
    return executorService;
  }
}
